An efficient implementation of the harmonic balance method, using novel numerical algorithms, that are both robust and efficient, coupled with analytical expressions developed for the elements of the Jacobian matrix, is presented. The approach possesses excellent convergence property and speed. Simulated performances using the developed approach for a 10-GHz GaAs MESFET amplifier are found in good agreement with the measured results. Developed techniques should be very useful for analyzing nonlinear microwave as well as optical components.